SQL injection in ClickHouse-backed meter definitions in OpenMeter OpenMeter before v1.0.0-beta.228 on all platforms allows a remote unauthenticated attacker to access or modify metering event data, and potentially cause denial of service, via crafted user-controlled JSONPath values submitted to meters API.

Affected: Go: github.com/openmeterio/openmeter

### Summary

An authenticated tenant can inject arbitrary SQL through the `valueProperty` or `groupBy` fields of `POST /api/v1/meters`. The injection passes the application's JSONPath validation check and executes against the shared ClickHouse database, which contains event data for all tenants with no row-level security. Any authenticated tenant can read or write every other tenant's metering data.

### Details

`openmeter/streaming/clickhouse/utils_query.go:15` builds a ClickHouse `SELECT` by interpolating user input with `fmt.Sprintf`:

```go sb.Select(fmt.Sprintf("JSON_VALUE('{}', '%s')", sqlbuilder.Escape(d.jsonPath))) ```

`sqlbuilder.Escape()` (go-sqlbuilder v1.40.2) only replaces `$` → `$$` to prevent collisions with the library's own argument placeholders. It does not escape single quotes. A single quote in the input closes the string literal, and subsequent tokens execute as raw SQL. `sb.Build()` always returns an empty `args` slice — the query is never parameterized.

The payload must be prefixed with a valid JSONPath expression (e.g. `$.foo`) because ClickHouse raises error code 36 (BAD_ARGUMENTS) on an empty JSONPath string, which `ValidateJSONPath` silently treats as "invalid JSONPath" and returns early — before the injected branch can execute.

Working payload: ``` $.foo') UNION ALL SELECT toString(sleep(3)) FROM system.one -- ```

Generated SQL: ```sql SELECT JSON_VALUE('{}', '$.foo') UNION ALL SELECT toString(sleep(3)) FROM system.one --' ```

Fix — replace…